This application claims the priority of Korean Patent Application No. 2004-9838, filed on Feb. 14, 2004, which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a field emission backlight device and a method of fabricating a field emission backlight device. More particularly it relates to a field emission backlight device for a Liquid Crystal Display (LCD), and method of fabricating such a device.
2. Description of the Related Art
LCDs sometimes include a backlight device installed at a rear surface to supply white light. Typically, a cold cathode tube is used as the backlight device. In many instances, such a backlight device may be appropriate, but it is not very slim.
As shown in FIG. 1, the conventional backlight device includes spacers (not shown) between a front substrate 1 and a rear substrate 4. A wall (not shown) is sealed between the front substrate 1 and the rear substrate 4. A cathode electrode 5 is installed in a type of a surface electrode or a stripe on the rear substrate 4, and a field emission source (such as a carbon nanotube) 6 is disposed on the cathode electrode 5. An anode electrode 2 is disposed on the front substrate 1. A phosphorous layer 3 is coated on the anode electrode 2.
When a predetermined voltage is applied to the cathode electrode 5 and the anode electrode 2, electrons emit from the field emission source 6 to excite the phosphorous layer 3. Light emitting from the phosphorous layer 3 passes through the phosphorous layer 3, the anode electrode 2 and the front substrate 1 to be incident on the LCD.
In the conventional flat backlight device, electrons concentratedly emit at an edge of the cathode electrode 5, thereby causing non-uniform luminance.
Specifically, due to the large-size of the LCD, a drawback of non-uniform luminance is increasingly serious.
U.S. Pat. No. 5,760,858 discusses a triode structure of a field emission backlight device having good energy efficiency. The field emission backlight device is combined with a liquid crystal panel, thereby making it possible to perform backlighting with a low consumption power and providing high uniform luminance due to a whole flat-surface emission way.
However, the backlight device of U.S. Pat. No. 5,760,858 has the same structure of Field Effect Display (FED) employing a Spindt type. Since this kind of structure of the backlight device is fabricated together with the LCD panel, the fabrication method thereof is complicated. Specifically, the field emission structure is fabricated using a semiconductor fabrication process, thereby increasing fabrication cost and providing a low yield considering the relatively simple structure of the LCD panel.